i got the correct codes which could solved my problem, in previously posted questions : How do I get an image to fade in and out on a scroll using jQuery?
var divs = $('.banner');
$(window).scroll(function(){
if($(window).scrollTop()<10){
divs.stop(true, true).fadeIn(5000);
} else {
divs.stop(true, true).fadeOut(5000);}
});
now I can't understand how to implement this code in blogger.